This invention relates generally to methods and systems for treating condensate liquid created in air conditioning equipment which is collected and removed in drain pans and drain conduits, and in particular to such systems wherein a chemical is provided to prevent the growth of algae, mold, mildew or other microorganisms within the drain pan or conduits, which may lead to blockage of the drain system. Water vapor condenses on the cooling coils of an evaporative air conditioner during the air cooling operation. This condensate drips from the cooling coils into a drain pan, also commonly referred to as a drip pan, collection pan or condensate pan, which is positioned beneath the coils within the air handling unit. Typically a drain port and an auxiliary port are provided in the equipment housing, the drain port providing a communication means for condensate liquid to pass from the drain pan into a drain conduit, such that the condensate liquid is easily removed from the drain pan for disposal, with the condensate liquid typically being discharged on the exterior of the building. The outflow may be accomplished by gravity or a pump may be utilized to move the liquid through the drain conduit.
It is not uncommon for microorganisms, primarily algae, to grow within the drain pan or drain conduit. This can lead to blockage of the drain port or the drain conduit. When this occurs, the condensate liquid gathers in the drain pan until it overflows and damages the surrounding floor, wallboard, carpet, etc. To unblock the drain port or the drain conduit, it is known to insert elongated members into the drain conduit to physically remove the blockages.
Other techniques are to blast a jet of pressurized air into the drain conduit or to use a wet vacuum to suction obstructions from the drain conduit.
To prevent the growth of microorganisms in the drain pan and drain conduit of an evaporative air conditioner system, it is known to introduce chemicals into the drain pan. One basic method involves pouring a solution, bleach for example, directly into the drain pan at regular intervals. Another involves placing solid chemical tablets into the drain pan, the solids dissolving over time. More complicated methods involve providing external liquid reservoirs with tubing arranged to deliver small amounts of chemical solution into the drain pan, either upon manual activation or using timer systems. Examples of known systems are shown in U.S. Pat. Nos. 6,892,907, 6,487,867, 5,514,344, 4,962,778 and 2,709,522. These systems require an outside water source to provide water within the air conditioning system.
Periodically dispensing small amounts of a chemical solution into the drain pan is a highly efficient method to maintain the drain system in optimum working order, but since condensate air conditioners do not require connections to the building water system for operation of the air handler unit, the user must buy, transport and store bulky liquid-filled containers of the chemical solution or must mix a solid chemical with water to create the chemical solution. Even more complicated systems may require the addition of a water line to provide the liquid to the treatment system.
It is an object of this invention to address the problems set forth above by providing a condensate drain pan treatment apparatus and method that creates a chemical treating solution from solid form chemicals (blocks, tablets, granules, powders, gels) by recycling condensate water from the drain system itself of a system that has no external water supply, the recycled water being combined with the solid chemical to produce the liquid chemical, which is then delivered into the drain pan in order to treat the entire drain system. It is a further object to provide such an apparatus and method such that the condensate water is automatically treated.